The present invention relates to a suction transporting device. More particularly, it relates to a suction transporting device which uses a suction force for transporting solid or liquid particles by a carrying agent.
Suction transporting devices of the above mentioned general type are known in the art. In known transporting devices air or water from the environment are normally used as carrying agents. One example of a transporting device of this type using air as a carrying agent for transporting solid or liquid particles is a dry-wet vacuum cleaner. As an example of a suction transporting device using water as a carrying agent for transporting solid particles is a suction dredge. A suction transporting device basically includes a source of suction for example a fan driven by an electric motor and a transporting line formed as a hollow elongated body. The device may also have a suction nozzle attached to the front end of the transporting line and adapted to intake the carrying agent with the material to be transported. The efficiency of transporting when using such a suction device is determined primarily by a magnitude of a suction force which it develops at the surface from where the material to be transported is taken in by the suction nozzle. The strongest suction force in a particular suction device is obtained when the edge of the suction nozzle has a good contact with the surface. However, due to a strong suction force developed by such a nozzle, it sticks to the surface and as a result it becomes very difficult and sometimes impossible to move the nozzle along the surface.
Various means are used to reduce sticking and to achieve better mobility of a suction nozzle. For example, special parts are made in the edges of the nozzle, or the nozzle is kept elevated above the surface. When cutting or elevating of the suction nozzle is not desirable, an adjustable slot with a valve body is made in the wall of the transporting line as disclosed for example in the U.S. Pat. No. 3,048,876. The above means increases the mobility of the suction nozzle, but at the same time, permanently reduces the suction force at the surface where the material is being taken, and therefore permanently decrease the efficiency of a suction transporting device during operation.